The present invention relates to color filters for image sensors, and in particular to barriers between color filters in a color filter array.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. Conventional image sensors are fabricated on a semiconductor substrate using complementary metal-oxide-semiconductor (CMOS) technology or charge-coupled device (CCD) technology. The image sensors have arrays of pixels. Each pixel has a photosensor such as a photodiode.
A color filter array is formed over the photosensors with sensitivity to a certain range of wavelengths. The color filters are typically red, green, or blue color filters that select for red, green, or blue light, respectively.
As technology advances and pixel sizes shrink, the pixels may become less tolerant of variations in the lateral extent of the color filters. Undesirable diffusion or chemical reactions can occur between adjacent color filters. Barriers can sometimes be formed between adjacent color filters. However, image sensors having conventional color filter barriers formed from metal may have performance characteristics that are less than ideal.
It is desirable, depending on the size of an image sensor device, to have improved barriers between color filters in a color filter array.